1. Field of the Invention
This invention relates to stitch knitted fabric in which a filling is knitted through with front and back guide bar warp thread systems.
The invention has particular reference to stitch bonded fabrics in which the filling is a fibre fleece, usually a cross-folded card web. Other types of filling, of course, include for example a sheet of weft threads or a sheet of foamed plastics material.
2. Description of the Prior Art
Two guide bar fabrics have been manufactured in which the front and back bars knit with different stitch systems. Reasons for using two independent thread systems in stitch bonded production include the production of more interesting surface texture or pattern effects, improved weft-way strength, and the avoidance of laddering. In a well known arrangement, one bar knits pillar stitch while the other bar knits tricot stitch. In another arrangement, both bars knit mirror-image systems extending over two or more needles.
Pattern effects are also achieved--even in single guide bar stitch bonding machinery--by the use of half set or otherwise incomplete threading. Missing out a single thread occasionally from a ground of pillar stitch gives rise to a lengthwise stripe or rib. Pattern effects have also been produced by the incorporation of a laid-in effect thread substantially without tension in a ground of pillar stitch, which shows up for example as a zig-zag line or a wavy stripe, if several such threads are laid-in in a block.
However, stitch bonded fleece fabrics, even with these various pattern or texture effects, have always had a relatively flat surface or an essentially lengthwise ribbed texture somewhat resembling a cord cloth. Lengthwise ribbiness can to some extent be reduced by avoiding the pillar stitch and knitting tricot stitch formation on both bars--or perhaps more complicated zig-zag patterns--but the physical properties of such fabrics, particularly as regards lengthwise stability, are considerably inferior to those of fabrics that have pillar stitch on one bar.